Systematic Review of Naloxone Dosing and Adverse Events in the Emergency Department.

BACKGROUND: Experts recommend using the lowest effective dose of naloxone to balance the reversal of opioid-induced respiratory depression and avoid precipitated opioid withdrawal, however, there is no established dosing standards within the emergency department (ED). OBJECTIVES: The aim of this review was to determine current naloxone dosing practice in the ED and their association with adverse events. METHODS: We conducted a systematic review by searching PubMed, Cochrane, Embase, and EBSCO from 2000-2021. Articles containing patient-level data for initial ED dose and patient outcome had data abstracted by two independent reviewers. Patients were divided into subgroups depending on the initial dose of i.v. naloxone: low dose ([LD], < 0.4 mg), standard dose ([SD], 0.4-2 mg), or high dose ([HD], > 2 mg). Our outcomes were the dose range administered and adverse events per dose. We compared groups using chi-squared difference of proportions or Fisher's exact test. RESULTS: The review included 13 articles with 209 patients in the results analysis: 111 patients in LD (0.04-0.1 mg), 95 in SD (0.4-2 mg), and 3 in HD (4-12 mg). At least one adverse event was reported in 37 SD patients (38.9%), compared with 14 in LD (12.6%, p < 0.0001) and 2 in HD (100.0%, p = 0.16). At least one additional dose was administered to 53 SD patients (55.8%), compared with 55 in LD (49.5%, p < 0.0001), and 3 in HD (100.0%, p = 0.48). CONCLUSIONS: Lower doses of naloxone in the ED may help reduce related adverse events without increasing the need for additional doses. Future studies should evaluate the effectiveness of lower doses of naloxone to reverse opioid-induced respiratory depression without causing precipitated opioid withdrawal.

Acute chloroquine and hydroxychloroquine toxicity: A review for emergency clinicians.

BACKGROUND: Acute chloroquine and hydroxychloroquine toxicity is characterized by a combination of direct cardiovascular effects and electrolyte derangements with resultant dysrhythmias and is associated with significant morbidity and mortality. OBJECTIVE: This review describes acute chloroquine and hydroxychloroquine toxicity, outlines the complex pathophysiologic derangements, and addresses the emergency department (ED) management of this patient population. DISCUSSION: Chloroquine and hydroxychloroquine are aminoquinoline derivatives widely used in the treatment of rheumatologic diseases including systemic lupus erythematosus and rheumatoid arthritis as well as for malaria prophylaxis. In early 2020, anecdotal reports and preliminary data suggested utility of hydroxychloroquine in attenuating viral loads and symptoms in patients with SARS-CoV-2 infection. Aminoquinoline drugs pose unique and significant toxicological risks, both during their intended use as well as in unsupervised settings by laypersons. The therapeutic range for chloroquine is narrow. Acute severe toxicity is associated with 10-30% mortality owing to a combination of direct cardiovascular effects and electrolyte derangements with resultant dysrhythmias. Treatment in the ED is focused on decontamination, stabilization of cardiac dysrhythmias, hemodynamic support, electrolyte correction, and seizure prevention. CONCLUSIONS: An understanding of the pathophysiology of acute chloroquine and hydroxychloroquine toxicity and available emergency treatments can assist emergency clinicians in reducing the immediate morbidity and mortality associated with this disease.

Found Down: Approach to the Patient with an Unknown Poisoning.

Approximately 30% of poison exposures reported to centers each year are either referred to or initiated within a health care facility. Among these exposures, undifferentiated poisoned patients are among the most challenging cases faced in the emergency department. Airway, breathing, circulation (ABCs) is central to the management of unknown poisoned patient. After initial stabilization, taking a systematic approach presented here may be beneficial to the clinician. This includes considering key additional history, a possible toxidrome, and data in the form of vital signs, physical examination, laboratory analysis, ECG, and imaging. After which a tailored approach to supportive care, decontamination, possible antidotes, and enhanced elimination techniques will improve outcomes.

Left Ventricular Regional Wall Motion Abnormality in the Setting of Acute Loperamide Overdose.

Loperamide is an inexpensive, over-the-counter antidiarrheal agent with emerging reports of overdose due to its opioid properties. Although it is considered by many patients to be safe, cardiotoxicity has been reported, prompting the United States Food and Drug Administration to release a warning regarding the arrhythmogenic potential of loperamide. We present a case of a 32-year-old male presenting in acute loperamide overdose and subsequent cardiac dysrhythmia with focal wall motion abnormalities on echocardiogram. This finding has not been previously reported in the literature and is unique in this clinical presentation. We also highlight the potential mechanisms for loperamide cardiotoxicity and its challenging management.